1. Field of the Invention
This invention relates to the fields of nanoparticles in chemistry and biology.
2. Description of the Related Art
Phosphors have utility for many applications but current phosphors have limitations. Those used for the purpose of light emission, for example, produce heat and therefore the light emission efficiency is limited.
Fluorescent-tagged phosphorescent biomarkers, such as fluorescent tags on core-shell nanoparticles (CSNPs), have great utility in various medical applications but suffer from various drawbacks. Those drawbacks include damage to the attached biological molecule, also known as photobleaching, as well as background fluorescence from excitation of other molecules in the vicinity of the biomarkers. Additionally, high energy excitation makes these biomarkers more complicated to use as the equipment for excitation requires more training for the practitioner.
Unmet Clinical and Scientific Need
A major advancement in the field of CSNPs used in a variety of fields would be to provide a core which has the option of being excited by safer and cheaper lower energy radiation. The lower energy radiation would minimize destruction to surrounding tissue when the CSNP is used in medical treatment. Additionally, if the CSNP is conjugated to a fluorescent tag, the lower energy radiation minimizes photobleaching and background fluorescence by surrounding molecules. Both of these result in a limitation on the sensitivity of the biomarker. A CSNP with a metal shell which does not inhibit phosphorescence from the phosphor core would further be an advancement as it would also improve the sensitivity of the application using the CSNPs because they could provide signal amplification. The gold shell also facilitates the attachment to biological molecules.